The present invention relates generally to filters and filtering methods, and more particularly, to a parallel decimator adaptive filter and filtering method such as may be used with all-rate gigabit-per-second modems, and the like.
Adaptive filtering is necessary in high-rate modems to suppress inter-symbol interference, remove analog filter dispersion, remove adjacent channel interference, perform pulse-shaping and interpolation, and mitigate co-channel interference. Nearly all low-cost digital integrated circuits are built from CMOS technology. Use of conventional technology limits the practical processing rate to about 100 MHz, the maximum clock rate of CMOS technology. There is no known conventional high-speed digital adaptive filter implementation that can operate on input data above 100 MHz.
It would be an improvement to have a parallel decimator adaptive filter and filtering method such as may be used with all-rate gigabit-per-second modems, and the like, that improves upon conventional filtering schemes.